Sound-absorbing wall or ceiling.



W. C. SABINE.

souwn ABSORBING WALL 0R CEILING.

APPLICATION FILED NOV. 29. 1915.

Patented NW. 21, 1916.

UNITED STATES PATENT OFFICE.

WALLACE c. SABINE, or BOSTON, MASSACHUSETTS, ASSIGNOR TO H. w. JOHNS; MANVILLE COMPANY. A CORPORATION or NEW YORK.

SOUND-ABSORBIN G WALL OR CEILING.

Specification of Letters Patent.

Patented Nov. 21, 1916.

Application filed November 29, 1915. Serial no. 64,149.

vention or correction of a certain class of where a finished and decorative surface is desired.

In some aspects the present invention is an improvement on that disclosed in U. S. Letters Patent No. 1,119,543, granted Dec. 1, 1914:, to Rafael Guastavino and myself as joint inventors of an improved wall or ceiling for auditoriums and the like, having in combination a supporting masonry structure and attached thereto an exposed inner layer of finished masonry, sponge-like in structure, the latter having pores which have rigidwalls and are'inter-communicating throughout the mass and openly penetrate the exposed finished surface, the said pores being of such proportional and variant dimensions that said inner masonry material possesses the property of absorbing inexcess often per centum of sounds lying in pitch between middle C and a third octave above the middle O. While the said patented invention has proven successful within a certain field of use the surface ap-v pearance produced-thereby is' not such as is always desirable on the walls and ceilings of relatively small rooms wherethe Wall and,

ceiling surfaces are so near to the inmates .as to clearly disclose their surface texture,

and the necessity for keeping down the porosity of the surface material described 1n the atent within 'certain'limits on account of similar considerations of external ape pearance also limits its acoustical efficiency drawings in which- Figure 1 is a cross section of a wall treat-- ,1 ed in accordance with one manner of'applying my invention, and Fig; 2 is a similar view showing a wallfltreated in accordance with another manner ofapplying myinven- 1, is the main wall structure which is directly proportional to such prosity.

Briefly stated, the present invention consists in the combination of porous masonry material of the general type disclosed in the prior patent referred to and an outer sound absorbing and transmitting fabric which is capable of producing a variety of decorative effects, and also of concealing the less attractive porous material behind it. As examples of such covering fabric, I would mention unsized burlap, rep, and

other textiles, though other fabrics could beused. This combination of a porous fabric,

with a porous masonry material,the latter having pores intercommunicating and of variant dimensions-results in an increased absorbingpower and the better correction of acoustical difficulties in auditoriums, offices, and the like, gives a more finished and decorative surface, and permits a less expensive and an acoustically more efiicient masonry beneath. The resultant combination permits the use of an unfinished porous masonry behind the vtextile material without reducing the decorative effect, and thereby reduces cost. It also permits the use of a more porous material similarly without reducing the decorative effect and thereby increases the acoustical efiiciency in that factor. The porous textile, or similar fabric used for surfacing is itself capable of absorbing a portion of the sound and of trans- -1nitting a very large proportion of sound not so absorbed to the'a-bsorbent masonry beneath, thereby further heightening the acoustical efiiciency of the combination.

The best formof construction-embodying my invention at present known to me is illustrated in the accompanying sheet of tion, '1

Throughout the drawings like characters indicate like parts,

which may be of any drdinary building mareference or backing ioa terial giving the desired. strength and gen-;

eral structural qualities. v

2, -,2, are sectionsor panels of porous sound absorbing masonry material such as is disclosed in Patent No. 1,119,543 before reunder a light tension suflicient to maintain a plane surface thereof, and the battens are oflset from the face of the wall proper soas to leave a narrow air space between the face of the masonry material 2, and the back of the fabric 4. In th construction shown in Fig. 2, the main wal 1, has a surface capable of receiving and holding nails, and the sections orpanels of porous sound absorbing masonry 2,. are held in place by nails 6, 6. This cheap and rapid method of attaching the porous masonry to the supporting 'Wall is rendered permissible by my invention without diminishing the decorative effect because the outer decorative fabric 4, covers up the nail heads.

The operation of my invention is easily understood from the foregoing description. When the sound Waves strike the outer fabric 4, a part thereof are absorbed thereby,

While other portions 'are transmitted to the porous gmasonry behind I the f decorative covering-and are absorbed thereby trans-Q mitted to the; main wall 1 Among the advantages of a wall constructed in accordance )vith this invenetion maygbe mentio'nedf thc fact thatthe id sired I absorptionof sound and the correctio of acoustical difliculty -arebbtained te atd g'ree greaterthanlby the use of the masonry materialalone or of, the ,textile. covering alone, and thatthe finished smooth and 0f a texture acceptable in 'fismall rooms andin many places Where an exposed masonry surface Would be architecturally incon ruous and unacceptable.

arious changes could be made in the details of the preferred construction herein shown and described Without departing from the substance of the invention so longas the principle of arrangement and operation of parts above set out, is retained.

If desirable for any reason the textile fabric may be hung more loosely than is indicated in the drawings and maycome in contact with the porous masonry beneath. The porous masonry also may be made in other forms, and by a difierent process from that described in Patent No. 1,119,543 hereinbefore referred to, and applied to the Wall while in a plastic condition, subsequently hardening and setting.

Havingdes'cribed my invention, I claim: 1. A sound absorbing wall or ceiling comprising in combination a layer of porous sound absorbing masonry material having a surface broken by open pores and devoid of s ary;

Witnesse s: I,

ANNA Q' A E Bun-Jam ELLIsJ' p a p :j I

' m res; c, s'A iNn'.

ing masonry material, single outer 'covering of fabric capable of decorative treatment a d: Pe m th ell heu w s tr tch ,under sufficient tensionto maintain. a plane ,isurface located. parallel to the 'masonrysun face,iand se ies of .widely'spaced supports f for saidfabric whichlproject rromthe wall, 1 lightly beyond the s rraeejof the porous 

